Miami's three congressional seats have been Republican strongholds. But in a tough year for the GOP, Little Havana can no longer be taken for granted

An older generation of émigrés is being tested by younger, more moderate voices.

It wasn't that long ago that Inocencia Coto was about the most predictable voter in America. In 2000 she and thousands of other Cuban Americans turned out in overwhelming numbers around Miami to help George W. Bush win the White House. Now 75, Coto is still sashaying to Celia Cruz CDs at the Goodlet Adult Community Center in Hialeah, a Cuban-exile enclave adjoining Miami that votes almost 90% Republican in national elections. But Coto says she's voting for a Democrat this fall. Her new hero is Raul Martinez, who is challenging eight-term incumbent Lincoln Diaz-Balart in the race for U.S. Representative...